Investments in Unconsolidated Joint Ventures (Statements of Operations of the Joint Ventures) (Details) - USD ($) $ in Thousands			12 Months Ended
		Oct. 31, 2023	Dec. 31, 2023		Dec. 31, 2022		Dec. 31, 2021		Dec. 14, 2023
Schedule of Equity Method Investments [Line Items]
Total revenue			$ 3,273,569		$ 3,108,581		$ 2,888,621
Expenses
Transaction costs			4,313		2,905		5,036
Depreciation and amortization			830,813		749,775		717,336
Total expenses			2,239,227		2,050,056		1,920,581
Other income (expense)
Losses from early extinguishment of debt			0		0		(45,182)
Interest expense			(579,572)		(437,139)		(423,346)
Gain on sales-type lease			0		10,058		0
Net Loss			291,424		1,020,584		631,932
Income (Loss) from Equity Method Investments			(239,543)		(59,840)		(2,570)
Straight Line Rent Adjustments			99,100		108,000		104,300
Above and below market rent adjustments, net			19,200		9,100		4,200
Unconsolidated Joint Ventures [Member]
Schedule of Equity Method Investments [Line Items]
Total revenue	[1]		612,589		512,078		383,649
Expenses
Operating			239,947		198,632		158,498
Transaction costs			301		837		470
Depreciation and amortization			197,228		181,041		147,121
Total expenses			437,476		380,510		306,089
Other income (expense)
Losses from early extinguishment of debt			(3)		(1,327)		0
Interest expense			(227,537)		(154,065)		(108,884)
Unrealized gain (loss) on derivative instruments			6,582		(1,681)		0
Gain on sales-type lease			2,737		0		0
Net Loss			(56,272)		(22,143)		(31,324)
Company's share of net income (loss)			(19,599)		(2,551)		(10,254)
Gain on Sale of Investments			0		0		10,257	[2]
Gain on Unconsolidated Joint Venture Investment			35,756	[3]	0		0
Gain (loss) on sale / consolidation			28,412	[3],[4]	0		0
Impairment loss on investment			(272,603)	[5]	(50,705)	[5]	0
Basis differential	[6]		(11,509)		(6,584)		(2,573)
Income (Loss) from Equity Method Investments			(239,543)		(59,840)		(2,570)
Straight Line Rent Adjustments			28,700		62,900		17,200
Above and below market rent adjustments, net			800		400		$ 400
Unconsolidated Joint Ventures [Member] | Unconsolidated Properties
Other income (expense)
Impairment loss on investment			272,600
Annapolis Junction NFM, LLC [Member]
Other income (expense)
Ownership Percentage							50.00%
Annapolis Junction NFM, LLC [Member] | Unconsolidated Joint Ventures [Member]
Other income (expense)
Gain on Sale of Investments							$ 10,300
Colorado Center [Member] | Unconsolidated Joint Ventures [Member]
Other income (expense)
Straight Line Rent Adjustments			1,500		$ 500		$ 800
Dock 72 [Member] | Unconsolidated Joint Ventures [Member]
Other income (expense)
Impairment loss on investment			50,700
200 Fifth Avenue JV LLC
Other income (expense)
Impairment loss on investment			$ 33,400
Ownership Percentage	[7]		26.69%
200 Fifth Avenue JV LLC | Unconsolidated Joint Ventures [Member]
Other income (expense)
Impairment loss on investment			$ 33,400
Safeco Plaza REIT LLC
Other income (expense)
Impairment loss on investment			$ 29,900
Ownership Percentage	[7],[8]		33.67%
Safeco Plaza REIT LLC | Unconsolidated Joint Ventures [Member]
Other income (expense)
Impairment loss on investment			$ 29,900
Platform 16
Other income (expense)
Impairment loss on investment			$ 155,200
Ownership Percentage	[7],[9]		55.00%
Platform 16 | Unconsolidated Joint Ventures [Member]
Other income (expense)
Impairment loss on investment			$ 155,200
360 PAS Holdco LLC
Other income (expense)
Impairment loss on investment			$ 54,000
Ownership Percentage	[7],[10]		71.11%
360 PAS Holdco LLC | Unconsolidated Joint Ventures [Member]
Other income (expense)
Impairment loss on investment			$ 54,000
Santa Monica Business Park [Member]
Other income (expense)
Ownership Percentage	[11]				55.00%
Santa Monica Business Park [Member] | Joint Venture Partner [Member]
Other income (expense)
Ownership Percentage									45.00%
Hotel Tower Developer LLC [Member]
Other income (expense)
Ownership Percentage			50.00%
Hotel Tower Developer LLC [Member] | Unconsolidated Properties | Hub on Causeway - Hotel Air Rights
Other income (expense)
Gain on sales-type lease		$ 2,700
Ownership Percentage		50.00%

[1] Includes straight-line rent adjustments of approximately $28.7 million, $62.9 million and $17.2 million for the years ended December 31, 2023, 2022 and 2021, respectively.

[2] During the year ended December 31, 2021, the Company completed the sale of its 50% ownership interest in Annapolis Junction NFM LLC. The Company recognized a gain on sale of investment of approximately $10.3 million.

[3] During the year ended December 31, 2023, the Company completed a restructuring of its ownership in Metropolitan Square, as described below in this Note 6.

[4] During the year ended December 31, 2023, the Company acquired its joint venture partner’s 45% ownership interest in Santa Monica Business Park, as described below in this Note 6.

[5] During the year ended December 31, 2023, the Company recognized an other-than-temporary impairment loss on its investments in Platform 16, 360 Park Avenue South, 200 Fifth Avenue and Safeco Plaza of approximately $155.2 million, $54.0 million, $33.4 million and $29.9 million, respectively, as described below in this Note 6. During the year ended December 31, 2022, the Company recognized an other-than-temporary impairment loss on its investment in the unconsolidated joint venture that owns Dock 72 in Brooklyn, New York totaling approximately $50.7 million.

[6] Includes straight-line rent adjustments of approximately $1.5 million, $0.5 million and $0.8 million for the years ended December 31, 2023, 2022 and 2020, respectively. Also includes net above-/below-market rent adjustments of approximately $0.8 million, $0.4 million and $0.4 million for the years ended December 31, 2023, 2022 and 2021, respectively.

[7] During the year ended December 31, 2023, the Company recognized an other-than-temporary impairment loss on its investment.

[8] The Company’s ownership includes (1) a 33.0% direct interest in the joint venture, and (2) an additional 1% interest in each of the two entities through which each partner owns its interest in the joint venture.

[9] At December 31, 2022, this entity was a VIE.

[10] On December 14, 2023, the Company completed the acquisition of all of one of its joint venture partners ownership interest. As a result of this acquisition, at December 31, 2023, the Company’s ownership includes (1) a 35.79% direct interest in the joint venture, (2) an additional 35.02% indirect ownership in the joint venture, and (3) an additional 1% interest in the entity through which the partner owns its interest in the joint venture. The Company’s partner will fund required capital until its aggregate investment is approximately 29% of all capital contributions; thereafter, the partners will fund required capital according to their percentage interests. At December 31, 2022, the Company’s ownership included (1) a 35.79% direct interest in the joint venture, (2) an additional 5.837% indirect ownership in the joint venture, and (3) an additional 1% interest in each of the two entities through which each partner owns its interest in the joint venture.

[11] During the year ended December 31, 2023, the Company completed the acquisition of its joint venture partner’s 45% ownership interest in Santa Monica Business Park, as described below in this Note 6 and Note 3.